There are VC-funded startups that fulfill a semi-real need, but lack any potential to become a real business. "Advertising" isn't a business model; it's a crutch one reaches for when an existing business isn't financially sustainable on its own.

Giphy should be an open source library or app, or perhaps a community-supported site, that people would use on occasion. Expecting it to drive traffic that justifies a VC-scale investment will only dilute a generally useful service and cause it to fall by the wayside when the VCs pull out.